Hartmann A, Kiskinis E, Fjällman A, Suter W
Novartis Pharma AG, Genetic and Experimental Toxicology, WSH2881.5.14, CH-4002, Basel, Switzerland.
Mutat Res. 2001 Oct 18;497(1-2):199-212. doi: 10.1016/s1383-5718(01)00256-x.
We use the comet assay as part of our genotoxicity screening battery for newly synthesized drug candidates. A dataset of more than 250 tests carried out with 75 drug candidates of various chemical classes was analyzed to elucidate the influence of cytotoxicity and compound precipitation on DNA migration in the comet assay. Using a V79 Chinese hamster cell line, 38 of the compounds were negative and 37 were positive in the comet assay. The reproducibility of test results between repeat experiments was 85%. Data on 72 tests with a negative call in which the compounds were tested up to highly cytotoxic concentrations demonstrated that cytotoxicity, as determined by Trypan blue dye exclusion and occurrence of cells with completely fragmented chromatin, did not lead to false positive test results. The majority (64.2%) of compounds with a positive call induced elevated DNA migration in the absence of excessive cytotoxicity. Compound precipitation was observed in 84 tests. In 88.1% of these cases, the test result at the precipitating concentration did not differ from that found at the highest soluble concentration. Half of the remaining 11.9% of contrary results (most of them weak effects) were not reproducible in the respective repeat experiment, indicating no or only a negligible influence of precipitation on test results. The data indicate that using V79 cells, the comet assay specifically detects genotoxic effects and is not confounded by cytotoxicity or compound precipitation under the conditions used.
我们将彗星试验作为新合成候选药物遗传毒性筛选组合的一部分。分析了用75种不同化学类别的候选药物进行的250多次试验的数据集，以阐明细胞毒性和化合物沉淀对彗星试验中DNA迁移的影响。使用V79中国仓鼠细胞系，38种化合物在彗星试验中呈阴性，37种呈阳性。重复实验之间测试结果的重现性为85%。关于72次呈阴性结果的试验数据，其中化合物测试至高细胞毒性浓度，结果表明，通过台盼蓝染料排除法和出现染色质完全碎片化的细胞所确定的细胞毒性，并未导致假阳性测试结果。大多数（64.2%）呈阳性结果的化合物在没有过度细胞毒性的情况下诱导了DNA迁移升高。在84次试验中观察到化合物沉淀。在这些情况的88.1%中，沉淀浓度下的测试结果与最高可溶浓度下的测试结果没有差异。其余11.9%相反结果中的一半（大多数为弱效应）在各自的重复实验中不可重现，表明沉淀对测试结果没有或只有可忽略不计的影响。数据表明，在使用的条件下，使用V79细胞，彗星试验能特异性检测遗传毒性效应，且不受细胞毒性或化合物沉淀的干扰。
